Tumbler locks



Dec. 23, 1969 B. BENNETT 3,485,068

TUMBLER LOCKS Filed Oct. 15, 1967 2 Sheets-Sheet 1 WVENTOK BE NARD BENNETT HTTORNEVS Dec. 23, 1969 BENNETT 3,485,068

TUMBLER LOCKS Filed Oct. 15, 1967 2 Sheets-Sheet 2 2 23 35 r +5 &

5 27 40 1H '8 T 24, 3s 52% 2 a 26 27 38 40 52 46 L2 M 3 as /4 I0 35 3b INVENTOK BERNARD BENNETT BY ATTORNEYS United States Patent U.S. Cl. 70-360 7 Claims ABSTRACT OF THE DISCLOSURE In a tumbler lock of the kind in which the locking element is actuated by a rotatable plug, which carries the tumblers, the plug carries a clutch element which is adapted to be brought into engagement with the locking element for actuating the latter. The clutch element is normally biased to a disengaging position so that the plug is freely rotatable. A blocking member carried by the plug engages stop means within the housing with the plug, and in order to engage the clutch element with the locking member it is necessary to move the blocking element to a position at which it will not engage the stop means; such movement of the blocking element is prevented by the tumblers except when the tumblers are moved by a key or other means to the appropriate unlocking con-figuration.

BACKGROUND OF THE INVENTION This invention relates to lock mechanisms, and is particularly concerned with lock mechanisms of the kind comprising a rotatable plug, which is usually adapted to receive a key, a locking element which may be rotated by the plug between locking and unlocking positions, a series of slotted tumbler elements or pins carried by the plug and individually movable within the plug so that their slots are normally misaligned but become aligned upon proper displacement by a key, for example, and a lock bar or abutment means which is engageable with the slots, when the slots are aligned, so as to permit rotation of the locking element by rotation of the plug. In known lock mechanisms of this kind the locking element is usually coupled to the rotatable plug so that it can be actuated whenever the plug is rotated. Rotation of the plug is normally prevented by the lock bar, which engages with a stop in the wall of the cylinder when the slots are misaligned. In order to permit rotation of the plug for actuating the locking element, it is necessary to align the slots in the tumbler elements or pins so that the lock bar can become disengaged from the stop as it moves into the aligned slots. Since the tumbler elements or pins must be displaced at the same time to respective predetermined positions, in order to release the mechanism, a large number of different locking configurations are available. In the case of a key operated lock the lock can only be opened readily with the proper key.

A key for such a lock has a plurality of fingers or projections of different lengths, corresponding to the number of tumbler elements or pins and the positions of their slots, and a lug which engages with a cooperating formation on the lock face, so that when the key is inserted into the lock the pins are displaced to their appropriate positions and the plug can be rotated by tuming the key.

A disadvantage of known locks of the kind referred to is that they can be picked by a skillful lock picker, who may probe each pin individually while trying to rotate the plug; when a pin is moved to its release position, this condition can be felt by the lock picker and so the complete combination can be determined.

Patented Dec. 23, 1969 It is an object of the present invention to provide a lock mechanism in which this disadvantage is overcome.

SUMMARY OF THE INVENTION According to the present invention, the plug is adapted to rotate the locking element, but such rotation is prevented if the tumbler slots are not suitably aligned, by means of a blocking element which engages a fixed stop, the blocking element being separate from the tumblers and normally disconnected therefrom. Thus, in one embodiment of the invention, the plug is freely rotatable within the plug housing and carries a clutch element which is normally disengaged from the locking element, but which may be brought into engagement with the locking element for actuation of the latter. Instead of a lock bar, a blocking element is mounted on the plug and is engageable with stop means positioned in the plug housing. The blocking element is movable from a first position, at which it engages the stop means and prevents engagement of the clutch element with the locking element, to a second position at which it permits the clutch element to be moved into engagement with the locking element, the blocking element in its second position engaging the slots in the tumbler elements, when the slots are aligned. The blocking element may conveniently take the form of a pivoted lever having an abutment at one end which is adapted to enter the aligned slots of the tumbler element, and an abutment at its other end which is adapted to engage a suitable stop in the plug housing.

The stop means may be constituted by a shoulder or ledge formed on the wall of the plug housing itself, or alternatively it may be constituted by a freely rotatable swivel mounted on the locking elements.

Since the blocking element is normally disconnected from the tumbler elements, it is impossible to feel the appropriate positions of the tumbler elements, because the plug encounters no sideways pressure as an attempt is made to turn it.

BRIEF DESCRIPTION OF THE DRAWINGS One embodiment of the invention is illustrated by way of example with reference to the accompanying drawings in which:

FIGURE 1 is a fragmentary perspective view, on a reduced scale, of a coin drawer of a coin-freed vending machine incorporating a lock according to the invention;

FIGURE 2 is a longitudinal section through the lock, the clutch of the lock being completely disengaged;

FIGURE 3 is a similar view of the lock in which the clutch has been partially displaced towards its engaging position by a key;

FIGURE 4 is a similar view of the lock in which the clutch is fully engaged;

FIGURE 5 is a section on line 5-5 in FIGURE 3; and

FIGURE 6 is a section generally on line 6-6 in FIG- URE 4.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIGURE 1, the coin drawer 10 of a coinfreed vending machine is slidably mounted in a compartment 11 provided in the machine. The compartment 11 has sidewalls 12 and 13 and front and rear walls 14 and 15. Means, not shown, are provided for supporting the drawer horizontally within the compartment. The drawer is locked by means of a locking element 16 rotatably mounted on a stub 17 projecting from the rear wall 18 of the drawer 10. The locking element 16 comprises a pair of latch members 19, which engage behind keeper 20 formed in the wall 15. The latch member 19 and keeper 20 are preferably formed as cam surfaces, as shown, which engage one another frictionally so as to minimize the risk of accidental unlocking by vibration orshock.

Referring now also to FIGURES 2 to 6, the lock actuating mechanism is housed in a horizontal mounting member or cylinder 23 which is rigidly mounted on the front wall 24 of the drawer 1t sov as to extend rearwardly therefrom, the cylinder preferably being brazed or welded in position. The cylinder 23 has a flanged head 25, which bears against the front of the wall 24.

Rotatably mounted within the cylinder 23 is a plug assembly comprising a rotatable plug body and movable parts carried thereby, The plug body 26 is cylindrical and is formed with an axially extending, square sectioned bore 27. The front endof the bore 27 is closed by a plate 28 providing a circular key-receiving face having a recess 30 and a horizontal slot 31 to receive parts of a key 29 as described below. Slidably arranged within the plug 26 are slotted pins or tumbler elements 33. In the present example there are four such grooves and four pins. Each pin 33 has a front head portion 34 against which a spring 35 bears to bias the pin towards the front end of the plug. The upper edge of each pin is formed with a deep slot 36 and a series of equally spaced shallow slots or notches 37. The position of the slot 36 is positions of the pins 33, when the blocking element is pivoted about the pivot pin 39. The inner end of the blocking element is provided with abutment means 41, which is adapted to engage a stop 42 as hereinafter described.

The locking element 16 is mounted on a rotatable shaft 43, the front end of which is formed with an exially extending toothed flange 44 constituting a clutch element. The rear end of the plug body 26 is formed also with an axially extending toothed flange 45, constituting a complementary clutch element to engage the clutch element 44. The two clutch elements are biassed apart by means of a helical coil spring 46, one end of which engages a washer at the rear end of the plug body 26, and the other end of which engages a washer 47 mounted on a freely rotatable swivel 49 which provides the stop 42. The swivel 49 is mounted at the forward end of the shaft 43. The plug body 26 is displaceable axially along the cylinder 23, but engagementbetween the clutch elements is prevented by the abutment'rneans 41 which engages the stop 42. To permit engagement between the clutch elements and 44, it is necessary to move the blocking element 38 from its first position, shown in FIGURE 2, to its second position, shown in FIGURE 4, so that the abutment means 41 will enter a recess 50 in the face of the stop 42.

The blocking element 38 is biassed towards the first position by a blade spring 51, and a coil spring 52 is provided for biassing the blocking element towards the second position. The spring 51 is stronger than the spring 52,- but its a ction'is reduced when the plug is moved along I the cylinder, so that the spring-'52 becomes effective to move the blocking element down into engagement with the tumbler elements. I

The key 29 comprises essentially a handle portion 53,

and a cylindrical shank 54' having 'a lug 55 adapted to engage in the recess 30 of plate 28, and a horizontal row of four fingers 5 6" of different lengths projecting forwardthe key 29, the clutch elements 44 and 45 are prevented I fromengaging by the abutment means 41 which engages the stop 42. Therefore the plug can rotate freely in- .4. dependently ofthe'locking element 16. It is true that the action of the springs 51 and 52 is such as to bias the blocking element downwardly as the plug is displaced axially along the cylinder, but full movement of the blocking element to its second position is prevented by the abutment 40 engaging'the' tumbler elements 33.

When the key :29 isinsertediii the lock, the lug 55 enters the recessi'lit) and the fingers 56 e nter the slot 31 of the plate 28. The fingers. 56 engage'the pins 33 and displace .-the pins 33 longitudinally, and their respective lengths are such that each pin 33 is displaced to a position at which its deepslot 36 is aligned with the downwardly extending abutment 40 of the blocking element 3.8, the slots thenbeing aligned with each other. As the plug 26 is moved along the'cylinder, the effect of the spring 51,is weakened so that the abutment 40 readily enters the aligned slots 36under'the action of the spring 52. The block ing element is thus moved completely to the second position, at which the abutment means 41 is aligned with the recess 50,, thus permitting the plug to be moved until the clutch element 45 engages the clutch element 44. The shaft 43 and the locking element thereon are now readily rotated by means of the key 29.

It .Will be noted that the keyshank 54 isprovided with a spring-loaded ball 57 which, whenthe ,key is fully inserted, engages behind the flange 25 to retain the key in the lock until it is positively withdrawn by hand.

It will be understood that the invention is not restricted to the particular embodiment described above by way of example, but envisages anytumbler lock in which a mov- .able blocking element is arranged to prevent engagement between thev locking mechanism and the'locking element proper, the blocking element being permitted to move to its unblocking position only when the tumblers are correctly positioned, as for example by a key.

What I claim is: i

1. A lock mechanism comprising:

(-a)]a mounting member;

(b) a (rotatable) .plug having an axis of rotation, the plug being mounted within the mounting member for rotation about said axis; 7

(c) a rotatable lock-actuating member;

(d) a clutch element carried by the plug and rotatable therewith for rotating the lock-actuating member, the clutch element being mounted for movementlin a direction parallel to the rotational axis of the plug from a first position in which it is disengaged from the lock-actuating member to a second position in ,whichit engages the, lock-actuating member;

(e) means biasing the .clutch element' towards its first Po t on; v t

(f) a series of slotted tumbler elements carried by the plug and spaced in'a direction transverse to said axis, the tumbler elements having a first configuration corresponding to a closed lock, in which the slots therein 7 are misaligned, and a second configuration correspondingto opening of the lock, in which the slots therein are aligned in a direction transverse to said axis; g

g) means biasing the tumbler elements towards their first configuration, the tumbler elements being mounted for individual movement" between said first and second configurations; I

(h) stop means carried within said mounting member; v (i) a movable blocking element carried by the'plug; (j) abutment means on said blocking element engagable -withthe stop means for p'reventingmovement of the clutch element to its second position;

(k) the blocking element having a first position at i which the abut'rnent means engagessaid "stop means "and a second position at which the abutment means is disengaged from the stop means; and

(l) a turnblerengaging abutment on the blocking element, which abutment is engageable with the tumbler elements 'to' prevent movement of the blocking element to its second position, and engageable with the aligned slots of the tumbler elements when the tumbler elements are moved to their second configuration.

2. A lock mechanism comprising:

(a) a mounting member;

(b) a (rotatable) plug having an axis of rotation, the plug being mounted within the mounting member for rotation about said axis;

(c) a rotatable lock-actuating member;

(d) means carried by the plug and rotatable therewith for rotating the lock-actuating member;

(e) a series of slotted tumbler elements carried by the plug and spaced in a direction transverse to said axis, the tumbler elements having a first configuration corresponding to a closed lock, in which the slots therein are misaligned, and a second configuration corresponding to opening of the lock, in which the slots therein are aligned in a direction transverse to said axis;

(f) means biasing the tumbler elements towards their first configuration, the tumbler elements being mounted for individual movement between said first and second configurations;

(g) stop means carried within said mounting member;

(h) a movable blocking element carried by the plug, said blocking element being pivotally connected to the plug for rotation therewith;

(i) abutment means on said blocking element engageable with the stop means for preventing rotation of the lock-actuating member by the plug;

(j) the blocking element being mounted for pivotal movement between a first position at which the abutment means engages said stop means and a second position at which the abutment means is disengaged from the stop means; and

(k) a tumbler engaging abutment on the blocking element, which abutment is engageable with the tumbler elements to prevent movement of the blocking element to its second position, and engageable with the aligned slots of the tumbler elements when the tumbler elements are moved to their second configuration.

3. A lock mechanism according to claim 2, wherein the rotatable plug is adapted to receive a key for displacing the tumbler elements from their first configuration to their second configuration.

4. A lock mechanism according to claim 3, including spring means carried by the plug, the spring means being adapted to be actuated by the key for biasing the blocking element towards its second position.

5. A lock mechanism according to claim 2, wherein the blocking element is a pivoted lever, the abutment means thereon being at one end of the lever and said tumbler engaging abutment being adjacent the other end of the lever.

6. A lock mechanism according to claim 5, wherein the blocking element extends along the rotational axis of the plug, and said stop means is a, freely rotatable swivel mounted coaxially with the blocking element.

7. A lock mechanism comprising:

(a) a mounting member;

(b) a plug having an axis of rotation, the plug being mounted within the mounting member for rotation about said axis;

(c) a rotatable lock-actuating member;

(d) a clutch element carried by the plug and rotatable therewith for rotating the lock-actuating member, the clutch element being mounted for movement from a first position in which it is disengaged from the lockactuating member to asecond position in which it engages the lock-actuating member;

(e) means biasing the clutch element towards its first position;

(i) a series of elongated slotted tumbler elements carried by the plug and extending parallel to the rotational axis of the plug, said tumbler elements being spaced in a direction transverse to said axis, the tumbler elements having a first configuration corresponding to a closed lock, in which the slots therein are misaligned, and a second configuration corresponding to opening of the lock, in which the slots therein are aligned in a direction transverse to said axis;

(g) means biasing the tumbler elements towards their first configuration, the individual. tumbler elements being mounted for movement between said first and second configurations;

(h) stop means carried within said mounting member;

(i) a movable blocking element carried by the plug;

(i) abutment means on said blocking element engagea- Me with the stop means for preventing movement of the clutch element to its second position;

(k) the blocking element having a first position at which the abutment means engages said stop means and a second position at which the abutment means is disengaged from the stop means; and

(l) a tumbler engaging abutment on the blocking element, which abutment is engageable with the tumbler elements to prevent movement of the blocking element to its second position and engageable with the aligned slots of the tumbler elements when the tumbler elements are moved to their second configuration.

References Cited UNITED STATES PATENTS 2,690,070 9/1954 Spain -421 3,410,123 11/1968 Jacob 70-364 FOREIGN PATENTS 872,276 7/ 1961 Great Britain. 1,333,207 6/1963 France.

MARVIN A. CHAMPION, Primary Examiner R. L. WOLFE, Assistant Examiner US. Cl. X.R. 

